Another VAC Master Thread

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mulveling

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I have one on order since Friday! I'm borrowing my dealer's unit in the meantime (for a 2nd time actually). For some reason the supplied 8416 tubes don't gel with me. They look like they should be great tubes, Amperex Made in USA frame grids with gold pins and orange "PQ" branding/logo. They look like a premium high-dollar 6922, but the date codes seem to indicate a late 1980s production, which I though indicated military use - so why would they need Amperex "PQ" branding in that case? Weird. Anyways I don't like them lol. I was starting to get a bit concerned until I popped in the cheap-and-cheerful Electro Harmonix 6922 (Upscale Audio Platinum Grade & Cryo), WOW there is it. There's the stellar preamp I was expecting! The sweetness from the Renaissance V (which also used the EH 6922 tubes) is all there plus it's a substantially cleaner more powerful sound from top to bottom.

So what's you guys' experience with tube rolling the Master? Fortunately it only uses a pair, which makes it more feasible to make a bid for some CCA's or Telefunkens. Did anyone else also have a big "meh" take on the 8416 tubes? I suppose it's also possible these 8416 have a lot of hours and are worn down.

Also I have a Renaissance SE phono stage that I've been in love with for 3+ years, so I didn't order the Master's phono stage option. But looking at the phono board in this loaner unit, holy cow! It uses the same beautiful mounted terminal board & hand wiring as the main circuit board, no green PCB here. It's not as polished eye candy as the Statement, but still looks like a work of art to me. So now I'm having second thoughts, though I'm gonna be loathe to sell my Ren phono stage (it's been a good friend to me). I haven't even hooked up the built-in phono to see how it sounds yet. I'm a bit afraid I'll love what I hear and have to drop yet ANOTHER large chunk of money. This is a Vinyl ONLY system, btw. What say you all?

This loaner unit may also have taken a bit of wear and tear on the road (brought round the audio shows when that was still happening), so at first its mute logo was bright MAGENTA instead of the usual red. And now it's reverted back to red? Weird. I'm guessing the Magenta was a bug not a feature (both blue and red lights on at same time)? It was kinda cool lol. The remote volume control doesn't always work 100% either. I trust that's not a typical issue for owners of this preamp?

Amps are Signature 200iQ monos, speakers Canterbury GR, cartridge Koetsu Coralstone diamond. My dream system, and I am so happy to complete the VAC signal chain. I should have stopped fooling around years ago and gotten on board to all VAC. Their current lineup is phenomenal. Kevin's voicing of his products is godly. If you're looking at VAC and on the fence, get off it :)

* Take note you need to flip a switch to go from 8416/12DJ8 types to 6922/7308/6DJ8 types, to avoid sending 12V to a heater spec'd for 6V :o
 
Congrats! The Master is the shizzle!


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Slowly rolling in more tubes. Results so far:

  • Amperex 8416 (USA): Didn't work for me. Seemed uninspired, a little dry and lacking the sweetness and lush midrange I expected. The date codes seem to indicate late 1980s manufacture, I'm not sure if I'm reading that right but they sure SOUND like late-1980s USA military productions tubes to me - bleh lol. Good points: they look cool. Unknown hours on these, maybe a contributing factor. I'll have to give them a 2nd try, as I get more familiar with the core sound of this unit, before writing them off.
  • Electro Harmonix 6922 gold-pin Platinum grade w/ Cryo (Upscale Audio): Sweetness, lush mids abound. Good sound overall. But unfortunately this tube eventually leaves you wanting for more air and detail.
  • Siemens 6DJ8 (West Germany), steel pins. Appears to be genuine frame grid construction. This had a little more detail and oomph than the EH tubes, I think it beats the EH, pretty nice tube overall but still leaves a nagging feeling there could be more.
  • Philips E88CC SQ gold pins (Holland) - Finally popped in this 1st pair last night from my small stash of "premium" 6922. WOW. This is clearly a next-level tube compared to the above. The other tubes might as well pack up and go home at this point. All the sweetness plus ALL THE DETAIL. Best clarity, air, dynamics musical flow - everything! Easily the best listening session I've had so far with the loaner Master. Like how could the sound get any better than these tubes in this VAC Master - it can't...can it?

Next up: I have a pair of 1960's Holland Amperex 7308 currently sitting on the doorstep at my girlfriend's home. I expect they'll be akin to the Philips SQ due to common Holland heritage? But could they even be better? Last time I heard Amperex 7308 it was the USA version and it was a world away in a Sonic Frontiers phono stage but they completely transformed that amp. Might also try Telefunken at some point, and a more premium Siemens. I won't bother with Mullards since their other types ALWAYS sound too dark/warm/wooly to me. The 1960s Holland Amperex tubes have generally be impressing me the most of all makes - sweetness with ALL OF THE DETAIL seems to be the common theme!
 
mulveling said:
Slowly rolling in more tubes. Results so far:

  • Amperex 8416 (USA): Didn't work for me. Seemed uninspired, a little dry and lacking the sweetness and lush midrange I expected. The date codes seem to indicate late 1980s manufacture, I'm not sure if I'm reading that right but they sure SOUND like late-1980s USA military productions tubes to me - bleh lol. Good points: they look cool. Unknown hours on these, maybe a contributing factor. I'll have to give them a 2nd try, as I get more familiar with the core sound of this unit, before writing them off.
  • Electro Harmonix 6922 gold-pin Platinum grade w/ Cryo (Upscale Audio): Sweetness, lush mids abound. Good sound overall. But unfortunately this tube eventually leaves you wanting for more air and detail.
  • Siemens 6DJ8 (West Germany), steel pins. Appears to be genuine frame grid construction. This had a little more detail and oomph than the EH tubes, I think it beats the EH, pretty nice tube overall but still leaves a nagging feeling there could be more.
  • Philips E88CC SQ gold pins (Holland) - Finally popped in this 1st pair last night from my small stash of "premium" 6922. WOW. This is clearly a next-level tube compared to the above. The other tubes might as well pack up and go home at this point. All the sweetness plus ALL THE DETAIL. Best clarity, air, dynamics musical flow - everything! Easily the best listening session I've had so far with the loaner Master. Like how could the sound get any better than these tubes in this VAC Master - it can't...can it?

Next up: I have a pair of 1960's Holland Amperex 7308 currently sitting on the doorstep at my girlfriend's home. I expect they'll be akin to the Philips SQ due to common Holland heritage? But could they even be better? Last time I heard Amperex 7308 it was the USA version and it was a world away in a Sonic Frontiers phono stage but they completely transformed that amp. Might also try Telefunken at some point, and a more premium Siemens. I won't bother with Mullards since their other types ALWAYS sound too dark/warm/wooly to me. The 1960s Holland Amperex tubes have generally be impressing me the most of all makes - sweetness with ALL OF THE DETAIL seems to be the common theme!
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Following! I’ll likely switch from stock to what you find best.


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I thought I had posted on my experience rolling tubes in the Master, but I went back to that thread today and found that I hadn’t. Sorry for not checking sooner.

My favorite tube in the Master is the Amperex 7308. A very balanced tube with detail, natural (but not excessive) warmth, a touch of liquidity without being slow. Amperex 6DJ8’s and 6922’s were pretty much indistinguishable from the 7308’s.

I liked Telefunkens a lot. My 2nd favorite tube. Seemed maybe a bit more detailed than the 7308 but that may have been due to being slightly brighter and drier. I could live with these if I didn’t have the Amperex 7308’s. Still very musical and enjoyable.

NOS Mullards were quite a bit warmer, blurred and lacked detail. I didn’t keep these in for long because they were too obviously colored and lacking detail. Had the same experience with Mullard 12AX7’s in the phono section. Seems to be the “house sound” of Mullards.

Siemens were OK but just didn’t have the musicality of the Amperex and Telefunkens. No magic.
 
Dth31 said:
I thought I had posted on my experience rolling tubes in the Master, but I went back to that thread today and found that I hadn’t. Sorry for not checking sooner.

My favorite tube in the Master is the Amperex 7308. A very balanced tube with detail, natural (but not excessive) warmth, a touch of liquidity without being slow. Amperex 6DJ8’s and 6922’s were pretty much indistinguishable from the 7308’s.

I liked Telefunkens a lot. My 2nd favorite tube. Seemed maybe a bit more detailed than the 7308 but that may have been due to being slightly brighter and drier. I could live with these if I didn’t have the Amperex 7308’s. Still very musical and enjoyable.

NOS Mullards were quite a bit warmer, blurred and lacked detail. I didn’t keep these in for long because they were too obviously colored and lacking detail. Had the same experience with Mullard 12AX7’s in the phono section. Seems to be the “house sound” of Mullards.

Siemens were OK but just didn’t have the musicality of the Amperex and Telefunkens. No magic.
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Though my experience with them is only 12AX7's and EL34's, I totally agree with your views on Mullards. I've liked them for short bouts but in the end they never work out for me. They're just too far on the side of dark / warm, without enough magic in other places to fully redeem themselves. The Russian Mullard 12AX7/EL34 acquit themselves very well for the money, but there too they have similar issues (seems that New Sensor likes to voice their Mullard brand warm in homage to the classic British Mullard tubes, which is cool) and they also have slightly less of the 3D holographic imaging and articulation of the NOS British versions. The Mullards' main use is as a band-aid for systems that tend towards brightness or have misbehaved tweeters (don't shoot me, it's happened in my own system!).

In the phono stage Kevin usually ships Penta-Labs (Shuguang make) 12AX7 and those are really really nice for stock (very well balanced), but for sure you can take it further here too with NOS. I need to get some Amperex/Holland 12AX7 to try here; I think they'll be spectacular. Actually I think Kevin might sometimes ship Russian Mullard 12AX7 in the Ren V built-in phono? It sounds good for sure but his amazing phono stages deserve better IMO.

I received my Herleen/Holland Amperex 7308 from Brent Jesse and they look nice. Also picked up a cheap used pair of USA Amperex 7308 on audiogon. Exciting! But no impressions yet until I go back home this weekend. Man the Telefunkens and CCAs are hard to find, huh?
 
I purchased my Amperex 7308/6DJ8/6922 tubes from Brent Jesse too. Excellent service and tubes have always tested well on my tube tester. Ships fast, too.

I seem to gravitate toward 6922 line stages for some reason and have accumulated quite a few over the years. I shouldn’t have to buy more in my lifetime!
 
Yes, the topic of tube type choice for linestages (and then again for phono stages) is interesting in its own right. 12AU7 gain is just right but I simply don't like that tube. 12AX7 is awful for linestage duties; way too much gain (but GREAT for RIAA phono stages!). 12AT7 and 12AY7 are OK but nothing exciting, and probably still with too much gain. 6SN7 can be lovely but the vintage greats are almost impossible to find with low enough noise and microphonics for a gain slot. 6H30 are wonderful but there's a limit to how much "sweetness" you can draw out of them and there are virtually NO tube rolling options - what you get, is what you get. 6922 seems like the best combination of attributes for a world-class linestage, and then Kevin (thankfully) kept the tube count down, and removed the need for cathode follower outputs, by using Lundahl I/O transformers.

To be honest it made me think back to my Renaissance III days and wonder how the heck it managed to sound as good as it did with an awful tube complement of 4x 12AX7 and 2x 12AU7 :D The Master is much, much better - no doubt. But that old Ren III was the first to open my eyes onto Kevin's world-class phono stages.

I am building a little stash now of 6922, just to keep my Master supplied for the long-haul. The Amperex/Philips SQ E88CC are my baseline now - no need to go lower! :lol:
 
So I had a funny little VAC Master mishap while hosting a local audio buddy at my place for the first time.

The system was all warmed up, ready to drop the Koetsu and render the "all VAC" phono/pre/amp sonics for my friend. Needle drops, no sound. Check all input settings, no sound. Check all cables, no sound. Try switching to the back arm with Ortofon A90, no sound. And by "no sound" I mean that miniscule amount of bleed-through scratchy sound that happens when you have preamp mute engaged while playing music. Lots of apologizing, "this has never happened before", "VAC gear is usually so reliable", soft cursing, staring vacantly at cable connections which are 100% correct, trying to remain cool (lol). So after all manner of checking and rechecking, we figure the only thing that could cause this same behavior in BOTH channels is either phono or preamp power supply or a bad mute relay in the Master.

In goes the ARC Reference 6 which I haven't sold yet. It works!! Eh, it still sounds OK. But man I get a lot more top-end energy, drier midrange, and a little boominess to the bass, compared to the Master. The Master sounded so wonderful the night before! What happened?!

So 30 minutes before my friend has to leave, we decide to put the Master back in and see if the supposed bad relay might be coaxed to work again. Drop the needle...nope. Wait a minute. That stupid "Cinema" knob is staring at me. "Click". FINALLY, THERE IS SOUND! Lol.

So here's what happened:
  • It's the night before. Long & wonderful listening session until 3 AM, with lots of drinks.
  • Time to shut the system down; I fumble/feel for the Master's power knob
  • My hand finds the Cinema knob first (right above Power knob, same shape and feel and switch ergonomics). "Click". Oh wait, the VAC logos are still on.
  • Oh THIS one below is the power knob. "Click". Now it's off, yay.
  • I inadvertently leave Cinema-bypass switch ENGAGED for tomorrow.
  • I've never ever used Cinema-bypass on anything as I have no need for it in a pure 2-ch system. So it's not something I check for in my troubleshooting list. It has the same effect as the Mute function, except with no visible indicator!

My only complaint about the Master is I wish it didn't have that damn Cinema switch. Couldn't it be something else, like a Mono mode (with visual/logo indicator)? Or even just switch in a different pretty color for the VAC logos? :)
 
Haha, that happened before when my dealer brought over VAC pre demo unit to my place.

He ended took back for ‘repair’ and next day he told me nothing wrong, just the cinema mode got engaged
 
stargazerang said:
Hi anyone knows the input impedance of the pre amp? It’s not stated in the manual or website
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It uses Lundahl input transformers, and I don't know if those are before or after the Alps RK50 potentiometer (I'd guess before?), so it might not be a simple as a fixed number. Just email or call VAC and they'll give you the rundown. I'd imagine Kevin, in his wisdom, has set it up to be "sufficiently high impedance for the vast majority of applications" - which would typically mean >= 50,000 ohms, over most of the audible spectrum. Do you have a source you're particularly concerned about?
 
I’m using a VAC Master Pre with the built in phono and it’s the best I’ve ever heard. I don’t know what the Ren phono sounds like but you might not want to temp fate by trying the Master phono. 😀
 
Mcsnare said:
I’m using a VAC Master Pre with the built in phono and it’s the best I’ve ever heard. I don’t know what the Ren phono sounds like but you might not want to temp fate by trying the Master phono. 😀
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Yeah the onboard Master phono looks like a work of art with the hand-wired board. I asked Kevin Hayes directly, and he said there are sonic plusses and minuses to the Renaissance SE phono vs. onboard Master option. My dealer said the same. I can see myself that the Ren SE audio board has a bit more space for a couple larger capacitors. The Master phono has to make (very) minor concessions to fit in with the preamp board. On the other hand, its hand wiring is an advantage over the Ren's PCB board traces. And the Ren's need for an extra interconnect is not ideal, nor cheap. The parts quality and phono circuit is the same between the 2.

I couldn't get my Master loaner's phono option to work after (very) little effort, and already had the Ren SE, so decided to leave well enough alone and stick with my Ren. Now I kind of regret that because I could use the rack slot the Ren SE takes up.
 
One thing I've learned in months with my VAC Master - when used in combination with the 200iQ amps, it absolutely MUST be paired to a source that is fast & detailed with low distortion in low frequencies. Before the Master, I had 200iQ monos paired to an ARC Reference 6, VAC Renaissance SE phono, and Koetsu Blue Lace. In this system, the VAC phono's Lundahl LL1931 step-ups sounded too thin, lean, and a bit strident. I preferred the much plumper, warmer sounding SUTs like the EAR MC-3, Koetsu, and Bobs' Devices Sky. This resulted in good system balance. When I added the Master to replace Ref 6, those same plump SUTs resulted in a sound that was a bit sluggish, bloated, and blurred on music with hard and fast paced beats (hard rock, heavy metal). I didn't even think to re-try the VAC's own Lundahls, because prior experience led me to dismiss them to easily.

Then I acquired a Phison A2.120 solid-state amp. Very clean, fast and detailed amp. In place of the 200iQs, paired with Master/Ren/Koetsu, that Phison amp has amazing balance and synergy with the "plump" SUT's!

Recently I've tried the 200iQs back in place of the Phison again, and was initially frustrated by the same sluggishness and blurring of fast complex music. But that all-VAC midrange was amazing! Worth fighting for. So I finally realized I should try the Lundahls again, and...WOW. This is it. Amazing balance, stunning midrange and the. best. detail. I've ever heard from my system. So the amorphous core Lundahl MC SUTs have incredibly low distortion. It's not really a "revelation" per say, because obviously Kevin Hayes knew EXACTLY what he was doing designing the full VAC stack with Lundahls (it's very dangerous to 2nd guess Kevin's voicing choices). It just took me some time to come around because the habits I fell into from the Ref 6 days set me a bit off track :D

I've also heard the 200iQs and Ren V in a friend's system, and the VAC stack pairs beautifully with a great digital source too. So, lesson learned:
1. Your VAC amp+preamp stack needs a low distortion source with very clean & fast bass
2. The premium Lundahl amorphous core models (LL1931, 1931Ag, 1941, 1941Ag) have the cleanest, fastest bass of MC SUTs
 
I am currently trying the Tungsram 6922 from the tube store and a pair of Amperex 7308 PQ both big improvement and 2 of my favorite tubes in the master
 
fathead said:
I am currently trying the Tungsram 6922 from the tube store and a pair of Amperex 7308 PQ both big improvement and 2 of my favorite tubes in the master
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Tungsram 6922 sounds interesting - maybe I'll look for a pair. Amperex 7308, both the Holland and USA makes, are always a fabulous choice!
 
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